Tubular structure.



mfsaosaa. Patented Aug. a, 1899.

.1. H. BROWN.

TTTTTTTTT BUCTURE JOHN II. BROIVN, OF READING, PENNSYLVANIA.

TU-BULAR STRUCTURE.

.SPEGIFICATION forming parfi of Letters Patent N0. 630,585, dated. August 8, 1899 A plicatim1 filed November 12, 1898. Seria1 N0. 696,215. (N mode1fi T( IIZZ w7mm it may ooncrrt:

Be it known that I, JOHN H. BROWN, a cibi- 7.en of the United States, and a, resident of Readixig, in the connty of Berks and State of Pennsylvania, have invented a new and Usef x11 Improvement in TnbularStructures, 0f which the following isa specification.

My invention relates to an improverne'nt in tubu1ar structures in which the Wall 0f the structure is formed by overlapping eurved seetions.

A praetical embodiment of my invention is lepresented in the accompanying drawings, in which-- v Figure 1 is a view f a tubular structurein end elevation, showing in connection there- With an inner -Iinihgtaube, a surronnding wire jaeket, and an exterior tubular jacket. Fig. 2 represents in end elevabion a tubular structure composed of a1ess number of over- Impping sections than the structure shown in Fig. l. Fig. 3 is a view in end and side elevation of a blank from Which one 0f the sections f a cylindrical tubulanstructure is formed. Fig. 4 is a sirnilar view showing the seetion bent into the shape which it assurnes when flhe seetions a1e assembled. Fig. 5 represent-s in end m1d side elevation a blank from which a tpered seption is formed. Fig. 6 is a, similar view showing t-he taperd section curved in the fo1m whiel1 it: assumes when the seetions are assembled, and Fig. 7 1s a.

' viewof a j;fpered lining-tube.

Th-e several secions which enter into and eompose the body of the tubnlar structure are of invo1ute o1 convolute shape in erosssection and the nmnber oft s'ections may be two 01 more, as found n'1ost expedient. \Vhen assembled 150 form the tubular structure, eaeh of the involute 01' convolute sections is arranged to'begin ab a point distant fronn the beginning of the precedipg seetionhhe distance of the two points 0f beginning from one another, measured along the Cireumference 0f the eirenmseribing circle, being such a part of the entire circumference as one is of the mnnber 0f sections used. For exampleif twoisecbions are used then the distance be- 'tween Ehe two points of beginning will be oneconsecubive seetions will be one-third of the circumference of the circumseribing ci1e1e, and so on. v

In using the term circumscribing circle I refer to a circle which is drawn with a radius equa1 to the distance betsween the outernnos't poin of the convolute Q1 irivolnte eurve and Lhe 'center froxn which Ehe com ro1ute is generated. Furthermore, in the manufacture of a tubular structure frorn sections so curved the thiekness of the severa1 crved seetions is a matter to be considered in its relation 130 the number ofseetions employed in order 110 maintaina Wall Of equal thickness in the com the eonvolute curve measure, as abovestated.

If three sections a1e so be employed,'eaqh shou1d be one-third of such distance, an

so on. v In the f011n shown in Fig. 1 wenty convolute sections a1e employed in the body 0f the tubular structure, and in the form shown in Fig. 2 fou1 soetions are employed.

F01 purposes of convenience rny present inven'oion will be explained by referenee 130 the struct-ure shown in Fig. 2. The several couvolute sectiohs there shown are represented by A A A A cixcle i s denoted by B, its' Center by b, and the radial 1ine f01 determining the thick ness of-the respective sections by b. In this instance eaeh secti'on has a thickness equ'al to one-quarber of the distance betwe'zen the points C O masnred 0n the radial line b.

. Furthermore, Ehe points of beginriin'g' of each 0f these involute sections will be one-quarter the Iength of the cireumference B of the circle, as sbown by 1ahe radial Iines extended from the center b t10 points exterior ro 11116 cireumference of the'circle.

The circumference of the In practice I have fouhd itdesirable to form the seveml involn'oe o'r convolute seo 

